Prepare changelog for v3.23.1

Author: paulbalandan

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this library will be documented in this file:
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [v3.23.1](https://github.com/NexusPHP/cs-config/compare/v3.23.0...v3.23.1) - 2024-06-16
+
+- Refactor AbstractCustomFixerTestCase
+
 ## [v3.23.0](https://github.com/NexusPHP/cs-config/compare/v3.22.1...v3.23.0) - 2024-05-18
 
 - Fix for phpstan